This invention relates to communications networks, particularly local area networks connecting office data processing equipment. In particular, it relates to a junction block permitting tap-in connection to a continuous communication line, for example of twisted-pair or other two-conductor wire.
In the rapidly growing field of office automation, using electronic data processing equipment, there is a growing use of local area networks, serving, for example, a single office building or portion of a building. In such networks, there is increasing use of twisted-pair wire as the communications line. Generally, when the network is installed in a building, such wire is strung throughout the building, for example, at baseboard level, and thereafter the equipment to be included in the network is connected to the communications line. Frequently, after installation, equipment is moved from office to office; additionally, it may be desirable to connect new equipment onto the line after the original installation.
In such cases, there is need for a simple means for removably connecting the office equipment to the communications line. Such means may take the form of a junction block connected to the line, accepting a conventional plug or similar plug-in terminal structure from the equipment to be connected into the line.
Prior art devices for such connection have had various disadvantages. Many such devices have required that the communications line be severed, each free end being stripped and prepared (as by twisting the wires comprising the conductor), and the prepared ends being separately connected (as by winding around a post) to terminals in the junction block. This process, to be accomplished reliably, requires a certain amount of technical expertise, which means that the ordinary office personnel are frequently not able to make the connection and therefore cannot freely move equipment around the office. Further, the process is time-consuming. In addition, the fact that the line is severed and connected through terminals means that the resistance of the line is increased by the presence of an additional connection. Finally, a connection made in this way is not easily reversible.
It is therefore an object of this invention to provide a junction block permitting tap-in connection to a twisted-pair communications line that does not require the line to be severed, that can be easily employed by persons without technical experience, and without using special tools, whose parts cannot be misassembled, and that adds only minimal resistance to the line. It is also an object to provide such a block that can be removed if desired, and that is reusable.
A further object of the invention is to provide a junction block means for connecting into a two-conductor local area network that has superior capacity to preserve the connection when subjected to axial tension on the line from outside the block.
It is also an object of the invention to provide such a junction block that is inexpensive to manufacture. Further, it is an object to provide a junction block that can easily be provided with a resistor to stimulate a full line, but that can thereafter be easily and nondestructively opened to remove the resistor and connect equipment into the network through the same block.